1. Field of Invention
The present invention relates to a circulation structure of a ball screw, and more particularly relates to a ball returning circulator of a ball screw.
2. Related Prior Art
The structure of a conventional circulation tube of a ball screw has been developed into a variety of types, however, there are still problems and defects.
For example, the circulation tube is in a curved tubular shape, and the entire structure of the circulation tube is difficult to be manufactured by using the plastic injection molding method. Therefore, the conventional circulation tube is usually manufactured into a two-piece structure. After each half tube is molded and finished individually, the two halves can be combined as a complete circulation tube. One prior art, TW 097145688 discloses that a circulation tube is combined by two members. However, in practical application experience, the robust level of this conventional structure is not ideal because the two members are partially combined by using holes to clamp columns therebetween. Therefore, when the two members are hit by rolling balls, the combination structure of the two members is often easily loosened, and the two members may be divided, which will affect the smoothness of the rolling process of the rolling balls.
Another prior art, U.S. Pat. No. 3,143,896A discloses a circulation tube structure of a ball screw, which is constructed by two half-tube as an upper part and a lower part. Both sides of the upper part have flanges forming holes for bolts locking and positioning. However, in practical application experiences, the flanges are directly connected to both sides of the half-tube, when the half-tube is operated under pressure and vibration, those forces will be transmitted directly to the flanges, and the locking bolts are easily vibrated and loosened.
Therefore, how to develop a new structure to resolve the above mentioned problems existed in the conventional circulation tube of the ball screw is still the goal the related industries needs to strive toward.